Why not let the members read Bob's actual report and make their own decisions? Though Bob's tests show that filters can differ in their ability to stop particles, it's not as extreme as comparing a completely clean after-filter patch to an unused filter patch.

I've been researching to determine if I should purchase a K&N filter (for my gas-drinker, not my TDI) and, after reading Bob's original article and looking at his photos, I found this particular photo to be misleading.